C57BL/6J-Dpp4^{em1(cre/ERT2)Jkpns}/J

Stock number: 039217
Product name: Dpp4-creER^T2
Research areas: Cardiovascular Research, Developmental Biology Research, Metabolism Research, Neurobiology Research, Research Tools

Description

Dpp4-creER^T2 knock-in mice have cre-ERT2-P2A inserted between the 5' UTR and exon 1 of the Dpp4 gene. They are useful for applications requiring tamoxifen-induced deletion of floxed sequences in arachnoid barrier cells (ABCs) of the brain and when studying the blood-cerebrospinal fluid barrier.

Detailed description

CRISPR/Cas9 generated Dpp4-creER^T2 knock-in mice have cre-ERT2-P2A inserted between the 5' UTR and exon 1 of the dipeptidylpeptidase 4 (Dpp4) gene. The insertion of cre-ERT2-P2A does not affect endogenous gene expression. These mice express cre-ERT2 in arachnoid barrier cells (ABCs). The arachnoid barrier is a component of the blood-cerebrospinal fluid barrier (B-CSFB) in the meninges and is composed of epithelial-like, tight-junction-expressing cells. The arachnoid barrier is positioned immediately beneath the dural border cells and forms a B-CSFB between the dura mater and cerebrospinal fluid (CSF) in the subarachnoid space (SAS). Restricted to the cytoplasm, cre-ERT2 can only gain access to the nuclear compartment after exposure to tamoxifen. Heterozygotes are viable and fertile with no overt phenotype. The donating investigator did not maintain a homozygous colony, it is unknown if homozygotes are viable and fertile (February 2024).

When these mice are bred with mice containing loxP-flanked sequence, tamoxifen-inducible Cre-mediated recombination will result in deletion of the floxed sequences in the Cre-expressing cells of the offspring.

For example, when bred to Ai6(RCL-ZsGreen) mice (Stock No. 007906), recombination is evident in polygonal cells tiling the brain surface after tamoxifen induction. No cre activity is detected prior to tamoxifen administration in the brain/dura.

The donating investigator also made a similar mouse line, Slc47a1-creERT2 mice (Stock No. 039218), which express cre/ERT2 in dural border cells (DBCs) of the brain.

Development

sgRNAs (AAGGAGCCGCCCGACCATGANGG and GCGGGGTGCACTCACCTTCANGG) were designed to insert a cre/ERT2 fusion gene (a Cre recombinase fused to a human estrogen receptor ligand binding domain) fused to a P2A self-cleaving peptide between the 5' UTR and exon 1 of the dipeptidylpeptidase 4 (Dpp4) gene. sgRNA, the cas9 protein, and a donor plasmid were introduced into the cytoplasm of C57BL/6J-derived fertilized eggs with well recognized pronuclei. Correctly targeted embryos were transferred to pseudopregnant females. Dpp4-creER^T2 mice were identified by PCR and Southern blot, and random insertions were removed. Mice were further backcrossed to C57BL/6J mice (Stock No. 000664) for at least 4 generations to develop the colony. Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes.

Allele

Symbol: Dpp4^{em1(cre/ERT2)Jkpns}
Name: endonuclease-mediated mutation 1, Jonathan Kipnis
MGI accession ID: MGI:7595997
Generation method: Endonuclease-mediated
Attributes: Recombinase-expressing; Inducible
Synonyms: Dpp4-creER^T2
Marker symbol: Dpp4
Marker name: dipeptidylpeptidase 4
Marker synonyms: ADABP; ADCP2; CD26; Dpp-4; DPPIV; THAM; TP103
Chromosome: 2
Strain of origin: C57BL/6J
Molecular note: Using CRISPR/Cas9 technology, a cre/ERT2 fusion gene with a P2A self-cleaving peptide were inserted between the 5' UTR and exon 1 of theDpp4 gene.